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Another Pennsylvania A3 Switcher

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crueby:
Great start!!  And the silver soldering is a very useful skill, comes in handy on so many parts, worth doing some practice pieces to get the process down at first.   :popcorn: :popcorn:

Kim:
Sorry to be late to the party here, I've been out of town for a while.

You've made good progress here. Those journal boxes look great!

I agree - the carbide end mills work great on steel.  I've mostly switched to carbide on my mill, at least for all the standard sizes. Though I still have a lot of HSS end mills and they work fine. But the carbide is much faster and better, especially on steel!

Which brings me to my next thought - looks like you're using steel instead of brass for a lot of the parts?  That's what I did, and I'm not sorry.  It has worked quite well for me.

Kim

JCvdW:
Thanks for the comments Kim. I decided to use steel where possible, as brass in small quantities and with more or less the right dimensions are very hard to come by (and expensive!) around here. It is assuring to hear that steel worked for you.

Chris I followed your advice and practised quite a bit of silver soldering until I could get more or less repeatable results using Kozo's guidelines. After settling on a process, silver soldering the truck columns was straight forward and quite satisfying!

The process (for future reference):

1. Heat the drilled and tapped parts to remove any residual cutting fluid trapped inside the holes that will form part of the joint.
2. Clean the surfaces to be soldered with sanding paper.
3. Add punch marks to one side of the joint to ensure a sufficient (50 micron) gap.
3. Pickle the cleaned surfaces.
4. Apply flux. If the flux does not readily adhere to the metal surface, it is not clean, so pickle again. Apply flux to the screws as well.
5. Screw the parts together. Use screws of the same material as the parts to be joined. Harder screws will complicate subsequent drilling operations...
6. Do not wipe off excess flux where the silver solder will be placed. Push a piece of solder into the flux next to the joint.
7. Apply heat to the bulkier side of the joint, opposite to the solder. Keep applying heat until solder flows and fills the joint. Heat must be sufficient to complete operation within 5 minutes, to prevent flux from disappearing.
6. Allow piece to cool completely before removing any other jig screws, to avoid breaking off screws that are stuck while hot.
7. Pickle to clean the soldered joint.

The completed truck columns:

Admiral_dk:
Success is always a great feeling  :ThumbsUp:   :cheers:

Per

crueby:
Excellent!  Sounds like the practice was well worth it - its a fairly easy process once you go through it a few times. One big thing I learned the hard way was that larger mass parts, and especially large copper parts, need a bigger torch to get the pieces hot enough quick enough to not burn off the flux.

 :popcorn: :popcorn:

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